diff --git a/homeassistant/components/flume/__init__.py b/homeassistant/components/flume/__init__.py
index 9a96233e6a9..a5911af3c8f 100644
--- a/homeassistant/components/flume/__init__.py
+++ b/homeassistant/components/flume/__init__.py
@@ -16,6 +16,7 @@ from homeassistant.core import (
     ServiceCall,
     ServiceResponse,
     SupportsResponse,
+    callback,
 )
 from homeassistant.exceptions import ConfigEntryAuthFailed, ConfigEntryNotReady
 from homeassistant.helpers.selector import ConfigEntrySelector
@@ -88,7 +89,7 @@ async def async_setup_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     }
 
     await hass.config_entries.async_forward_entry_setups(entry, PLATFORMS)
-    await async_setup_service(hass)
+    setup_service(hass)
 
     return True
 
@@ -105,10 +106,11 @@ async def async_unload_entry(hass: HomeAssistant, entry: ConfigEntry) -> bool:
     return unload_ok
 
 
-async def async_setup_service(hass: HomeAssistant) -> None:
+def setup_service(hass: HomeAssistant) -> None:
     """Add the services for the flume integration."""
 
-    async def list_notifications(call: ServiceCall) -> ServiceResponse:
+    @callback
+    def list_notifications(call: ServiceCall) -> ServiceResponse:
         """Return the user notifications."""
         entry_id: str = call.data[CONF_CONFIG_ENTRY]
         entry: ConfigEntry | None = hass.config_entries.async_get_entry(entry_id)